1. Field of the Invention
The present invention relates to a method for producing an α-alumina powder. More particularly, the present invention relates to a method for producing an α-alumina powder having a high α-ratio, large BET specific surface area to provide a small amount of α-alumina particles having necking.
2. Description of Related Art
An α-alumina powder is a compound-of the formula Al2O3 and has an α crystal phase. An α-alumina powder is widely used, for example, as a raw material for producing a sintered body such as a translucent tube. From the standpoint of improvement in the strength of a sintered body, α-alumina used as a raw material is required to have a high α-ratio, large BET specific surface area, and to provide a small amount of α-alumina particles having necking.
Conventionally, as a method for producing such an α-alumina powder, there is known a method of calcining an α alumina raw material in the presence of ammonium nitrate (Key Engineering Materials, Vol. 53–55 (1991), 462–468).
However, the properties of an α-alumina powder obtained by the conventional method are not satisfactory for producing a sintered body.